1. Field of the Invention
The present invention relates generally to printing presses and more particularly to inking blades for printing presses.
2. Background Information
European Patent Application No. 0 753 408 A1 describes a method for installing a metering device in a rotary press. In this method for mounting inking blades of a rotary press that cooperate with an ink duct roller, the objective is to produce a small, uniform clearance between each of the segments of the inking blade. EP 0 753 408 A1 achieves this objective by heating and subsequently cooling the inking blade segments, which are mounted side-by-side without any clearance.
In accordance with an inking blade configuration from European Patent Application No. 0 453 872 B1, inking blades are configured on carrier elements at an ink duct of a rotary press, the inking blade being secured by screws at the ink duct, and being adjustable in its longitudinal direction. A setting mechanism is used to deflect the inking blade out resiliently, transversely to its longitudinal surface, in each case making it adjustable, with clearance, with respect to a roller that dips into the ink duct. The inking blade is composed of flexible tongues, which are disposed in a side-by-side configuration and are adjustably secured to the carrier element in the longitudinal direction of the tongues, to compensate for wear. In a region provided for securing the tongue to the carrier element, each tongue is provided with a centrically placed slotted hole, which enables the tongue to be adjusted in the longitudinal direction at the carrier element. The length of each slotted hole is dimensionally designed to be shorter then the clearance between the edge of the carrier element facing the roller and the screw, provided for securing the carrier element, facing away from the roller.
It has been established that related-art inking blade configurations, whose individual inking blade segments are retained by a connecting element, such as a screw or the like, on a carrier beam (i.e., a supporting crosspiece), tend to experience relative movements with respect to the carrier beam. Although the related-art screw connections do clamp the contact surface of inking blade segments underneath the carrier beam, the inking blade segments are able to shift relatively to their clamped position at the carrier beam. This is highly undesirable, since any deterioration in the preset inking blade position alters the ink quantity determined by this position, the ink quantity being supplied via the particular inking blade segment of the ink zone in question. In addition, there is the risk of potential damage to the ink duct roller, as well as of abrasion gradually setting in at the front edge of the segment.
Starting out from the background information delineated above, in the case of an ink metering device having inking blade segments arranged by zones, the present invention is directed to improving the contact between inking blade segments and the carrier beams that support them, so as to rule out relative movements once a presetting operation is implemented.
The present invention thus provides an inking blade configuration for an ink feeding device of a rotary press, comprising a carrier beam provided at the ink duct, the inking blade being composed of segments, which are accommodated in a side-by-side configuration on the carrier element and which are adjustable relatively to a roller that dips into the ink duct, the individual inking blade segments being connected by connecting elements to the carrier element, characterized in that
a form-locking connection (13) is provided underneath the connecting
elements (8) in the contact region (9) of the contact surfaces (11, 12) of the
segments (2) and of the carrier beam (5).
The advantages associated with the present invention lie, inter alia, in that a relative movement of an inking blade segment with respect to the carrier beam of the inking blade is ruled out, in particular a rotation out of the right angle, in which the segments are secured in relation to the carrier beam. The design approach in accordance with the present invention reduces the premature wear experienced by the front edge of the segments, which, per inking zone, are able to be brought into contact with the ink duct roller, thereby prolonging the service life and durability of the inking blade segments.
In an advantageous embodiment of the idea underlying the present invention, the contact surfaces of the inking blade segment and of the carrier beam can be provided with a roughened surface, to enhance the friction that inhibits a relative movement between the contact surfaces. One aspires in this case to a roughest possible surface. Alternatively, a form-locking type connection is able to be achieved between the contact surfaces of the segments and those of the carrier beam in that linear elevations are formed on the bottom side of the segments and on the top side of the carrier beam. If the inking blade segments and the carrier beam are screw-coupled to one another or joined together in some other manner, the linear elevations intermesh and prevent a relative movement of the segment with respect to the carrier beam. The regions of the segments and of the carrier beam where these linear elevations are formed, can be hardened using setting methods, to prevent them from undergoing any positional change during assembly.
The aforesaid linear elevations extend advantageously in parallel to the carrier beam reaching under the individual segments. Even given a longitudinal extension of the linear elevations in the longitudinal direction of the inking blade segment, a relative movement of the segments with respect to the carrier beam is able to be prevented, ensuring that the right-angled alignment of the inking blade segments with respect to the carrier beam is not adversely affected, and that it is retained.
The form-locking connection between the segments of the inking blade and the carrier beam can also be constituted of a toothed formation that is manufactured with utmost precision. In this form-fit configuration of segment and carrier beam, the individual teeth flanks contact one another contiguously and counteract a relative movement between the inking blade segment and carrier beam. A hardening process can also be used to treat the flank surfaces of the teeth.
The inking blade configuration in accordance with the present invention can be advantageously employed in an ink duct of rotary presses, as used, for example, in printing units of rotary presses in the commercial or newspaper printing sector.